Robotics Competition at Jamia, New Delhi: Got a good Idea?

As you've seen, the bot needs to pick up and throw a TT ball.
A friend and I have formed a team to enter for this contest.
We have a basic robotic platform as well as a mechanism to pick up the ball ready.
We've run into trouble in the throwing part. Here's where you come in.
If you've got a good(and workable, implementable) idea as to how that can be done, please contact me at: mvharish14988@gmail.com
If we end up using your idea, you'll be a regular teammate, and anything we win will, of course, be shared equally.

If you are looking for the simplest possible solution, may I suggest you use two vacuum cleaners with their nozzles very close together - one as a suction device, the other as a blower. Switch on the suction one when you want to pick up the ball. Switch this off and the blower on when you want to throw it. Since the competition is on Sunday, you can wait till Saturday night to do this.

You see, the vacuum cleaners don't work in reverse.
I'll probably have to use an air blower that runs on AC.
But I'm hesitant to do so, as this is one of the only contests that allows AC to be used, and I want to build a mechanism that can be used in any contest.
Anyway, thanks a lot.
If anything else comes up, let me know.